Weak axis low-damage performance of seismic resilient rocking steel column base with friction connection

Abstract

Rocking column bases with friction connections are a critical technology employed in the low-damage design of steel structures. In this study, cyclic loading tests were conducted along the weak axis of the column, incorporating INITIAL, AFTERSHOCK, and REPAIR cases, with a maximum drift ratio of 3%. In the AFTERSHOCK case, both the sliding and maximum moments at the column base exhibited a significant decrease of 67% and 16%, respectively. To address the decrease in sliding strength attributed to the loss of bolt tension, Belleville Springs (BeSs) were employed, and the bolts were maintained within the elastic range. The results demonstrate that the hysteretic curves of the column base almost perfectly align in all three cases, revealing a strength loss of less than 2% and a significant enhancement in seismic resilience. This low-damage column base proves well-suited for deployment in regions with high seismic risk, especially for buildings subjected to continuous seismic excitation. A finite element analysis (FEA) model was developed to quantitatively evaluate the damage, sliding, bolt tension loss, and energy dissipation performance of the column base. Finally, a simplified flag-shaped analytical model was proposed to guide the design of such low-damage column bases, providing a basis for their integration into overall structural analyses.